In recent years, global sea level has been rising. This is in part due to increased water temperature leading to expansion. It is also due to water that has come from melting glaciers and ice sheets. The graph below shows the change in mean global sea level over time.

(Image source: NASA, 2017)

Suggestions for Student Discussion and Further Investigation

• Describe the overall trend of sea level, as shown in the graph above.
• Use the data in the excel file at the bottom of the page to create a graph of mean annual sea level relative to April 1997.
• Find the line of best fit for the relationship between mean annual sea level over time.
• At what rate is sea level increasing?
• Predict the sea level rise from 2015 to 2020.
• If sea level continued to rise at the same rate, what would the sea level rise from 1997 to 2100 be?
• What are many of the concerns about the projected sea level rise this century?
• What factors are contributing to sea level rise?
• What can be done to mitigate sea level rise?

Data

At the bottom of this page is an excel file of the mean annual sea level (relative to April 1997), as measured by satellite and corrected for seasonal effects. This data was obtained from http://dx.doi.org/10.5067/GMSLM-TJ123.

Curriculum Mapping

Mathematics and Science in the New Zealand Curriculum.